#1801 implement 'Signature Help' LS feature

ide/che-core-ide-api/src/main/java/org/eclipse/che/ide/api/editor/codeassist/CodeAssistProcessor.java

@@ -20,8 +20,7 @@
  * assisting process.
  * </p>
  *
- * @author <a href="mailto:evidolob@exoplatform.com">Evgen Vidolob</a>
- * @version $Id:
+ * @author Evgen Vidolob
  */
 public interface CodeAssistProcessor {
 
@@ -30,7 +29,7 @@ public interface CodeAssistProcessor {
      * specified location within the document that corresponds
      * to the current cursor position within the text view.
      *
-     * @param view
+     * @param editor
      *         the editor whose document is used to compute the proposals
      * @param offset
      *         an offset within the document for which completions should be computed

ide/che-core-ide-api/src/main/java/org/eclipse/che/ide/api/editor/editorconfig/DefaultTextEditorConfiguration.java

@@ -19,6 +19,7 @@
 import org.eclipse.che.ide.api.editor.partition.DocumentPositionMap;
 import org.eclipse.che.ide.api.editor.quickfix.QuickAssistProcessor;
 import org.eclipse.che.ide.api.editor.reconciler.Reconciler;
+import org.eclipse.che.ide.api.editor.signature.SignatureHelpProvider;
 
 import java.util.Map;
 
@@ -76,4 +77,9 @@ public QuickAssistProcessor getQuickAssistProcessor() {
     public ChangeInterceptorProvider getChangeInterceptorProvider() {
         return null;
     }
+
+    @Override
+    public SignatureHelpProvider getSignatureHelpProvider() {
+        return null;
+    }
 }

ide/che-core-ide-api/src/main/java/org/eclipse/che/ide/api/editor/editorconfig/TextEditorConfiguration.java

@@ -19,6 +19,7 @@
 import org.eclipse.che.ide.api.editor.partition.DocumentPositionMap;
 import org.eclipse.che.ide.api.editor.quickfix.QuickAssistProcessor;
 import org.eclipse.che.ide.api.editor.reconciler.Reconciler;
+import org.eclipse.che.ide.api.editor.signature.SignatureHelpProvider;
 
 import javax.validation.constraints.NotNull;
 import java.util.Map;
@@ -97,4 +98,11 @@ public interface TextEditorConfiguration {
      */
     @Nullable
     ChangeInterceptorProvider getChangeInterceptorProvider();
+
+    /**
+     * Return the {@link SignatureHelpProvider}
+     * @return the signature help provider
+     */
+    @Nullable
+    SignatureHelpProvider getSignatureHelpProvider();
 }

ide/che-core-ide-api/src/main/java/org/eclipse/che/ide/api/editor/signature/ParameterInfo.java

@@ -0,0 +1,37 @@
+/*******************************************************************************
+ * Copyright (c) 2012-2016 Codenvy, S.A.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *   Codenvy, S.A. - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.che.ide.api.editor.signature;
+
+import com.google.common.base.Optional;
+
+import javax.validation.constraints.NotNull;
+
+/**
+ * Represent a parameter of callable signature.
+ * Parameter can have label and optional documentation.
+ *
+ * @author Evgen Vidolob
+ */
+public interface ParameterInfo {
+
+    /**
+     * The label of this parameter. Used for UI.
+     * @return the parameter label.
+     */
+    @NotNull
+    String getLabel();
+
+    /**
+     * The documentation of this parameter.
+     * @return the human-readable documentation string.
+     */
+    Optional<String> getDocumentation();
+}

ide/che-core-ide-api/src/main/java/org/eclipse/che/ide/api/editor/signature/SignatureHelp.java

@@ -0,0 +1,44 @@
+/*******************************************************************************
+ * Copyright (c) 2012-2016 Codenvy, S.A.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *   Codenvy, S.A. - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.che.ide.api.editor.signature;
+
+import com.google.common.base.Optional;
+
+import javax.validation.constraints.NotNull;
+import java.util.List;
+
+/**
+ * Result of calculation of signatures, represent the signature of something callable.
+ *
+ * @author Evgen Vidolob
+ */
+public interface SignatureHelp {
+
+    /**
+     * One or more signature.
+     * @return
+     */
+    @NotNull
+    List<SignatureInfo> getSignatures();
+
+    /**
+     * The active signature
+     *
+     * @return
+     */
+    Optional<Integer> getActiveSignature();
+
+    /**
+     * The active parameter of the active signature.
+     * @return
+     */
+    Optional<Integer> getActiveParameter();
+}

ide/che-core-ide-api/src/main/java/org/eclipse/che/ide/api/editor/signature/SignatureHelpProvider.java

@@ -0,0 +1,48 @@
+/*******************************************************************************
+ * Copyright (c) 2012-2016 Codenvy, S.A.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *   Codenvy, S.A. - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.che.ide.api.editor.signature;
+
+import com.google.common.base.Optional;
+
+import org.eclipse.che.api.promises.client.Promise;
+import org.eclipse.che.ide.api.editor.document.Document;
+import org.eclipse.che.ide.api.editor.texteditor.TextEditor;
+
+import javax.validation.constraints.NotNull;
+
+/**
+ * Calculates signature information at cursor position.
+ *
+ * @author Evgen Vidolob
+ */
+public interface SignatureHelpProvider {
+
+    /**
+     * Requests to provide signature information
+     * @param document
+     *              the document where request called
+     * @param offset
+     *              the offset where request called
+     * @return the promise.
+     */
+    @NotNull
+    Promise<Optional<SignatureHelp>> signatureHelp(Document document, int offset);
+
+    /**
+     * Installs the SignatureHelpProvider on the given text view.
+     */
+    void install(TextEditor editor);
+
+    /**
+     * Removes the SignatureHelpProvider from the text view it has previously been installed on.
+     */
+    void uninstall();
+}

ide/che-core-ide-api/src/main/java/org/eclipse/che/ide/api/editor/signature/SignatureInfo.java

@@ -0,0 +1,43 @@
+/*******************************************************************************
+ * Copyright (c) 2012-2016 Codenvy, S.A.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *   Codenvy, S.A. - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.che.ide.api.editor.signature;
+
+import com.google.common.base.Optional;
+
+import javax.validation.constraints.NotNull;
+import java.util.List;
+
+/**
+ * Represents the signature of something callable. A signature can have label, like method name,
+ * a documentation and list of parameters
+ *
+ * @author Evgen Vidolob
+ */
+public interface SignatureInfo {
+    /**
+     * The label of this signature.
+     * @return
+     */
+    @NotNull
+    String getLabel();
+
+    /**
+     * The documentation of this signature
+     * @return
+     */
+    Optional<String> getDocumentation();
+
+    /**
+     * The parameters of this signature.
+     * @return
+     */
+    Optional<List<ParameterInfo>> getParameters();
+}

ide/che-core-ide-api/src/main/java/org/eclipse/che/ide/api/editor/texteditor/TextEditorOperations.java

@@ -79,4 +79,9 @@ public interface TextEditorOperations {
      * show quick assist and quick fix proposals for the current position.
      */
     int QUICK_ASSIST = 15;
+
+    /**
+     * Text operation code for requesting signature help for current cursor position.
+     */
+    int SIGNATURE_HELP = 16;
 }

ide/che-core-ide-app/src/main/java/org/eclipse/che/ide/CoreLocalizationConstant.java

@@ -833,4 +833,10 @@ public interface CoreLocalizationConstant extends Messages {
 
     @Key("action.convert.folder.to.project.description")
     String actionConvertFolderToProjectDescription();
+
+    @Key("signature.name")
+    String signatureName();
+
+    @Key("signature.description")
+    String signatureDescription();
 }

ide/che-core-ide-app/src/main/java/org/eclipse/che/ide/actions/SignatureHelpAction.java

@@ -0,0 +1,70 @@
+/*******************************************************************************
+ * Copyright (c) 2012-2016 Codenvy, S.A.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *   Codenvy, S.A. - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.che.ide.actions;
+
+import com.google.inject.Inject;
+import com.google.inject.Singleton;
+
+import org.eclipse.che.ide.CoreLocalizationConstant;
+import org.eclipse.che.ide.api.action.AbstractPerspectiveAction;
+import org.eclipse.che.ide.api.action.ActionEvent;
+import org.eclipse.che.ide.api.editor.EditorAgent;
+import org.eclipse.che.ide.api.editor.EditorPartPresenter;
+import org.eclipse.che.ide.api.editor.texteditor.HandlesTextOperations;
+import org.eclipse.che.ide.api.editor.texteditor.TextEditorOperations;
+
+import javax.validation.constraints.NotNull;
+
+import static java.util.Collections.singletonList;
+import static org.eclipse.che.ide.workspace.perspectives.project.ProjectPerspective.PROJECT_PERSPECTIVE_ID;
+
+/**
+ * Action for 'Signature help', in general should show signature of something callable.
+ *
+ * @author Evgen Vidolob
+ */
+@Singleton
+public class SignatureHelpAction extends AbstractPerspectiveAction {
+
+    private final EditorAgent editorAgent;
+
+    @Inject
+    public SignatureHelpAction(EditorAgent editorAgent, CoreLocalizationConstant constant) {
+        super(singletonList(PROJECT_PERSPECTIVE_ID), constant.signatureName(), constant.signatureDescription(), null, null);
+        this.editorAgent = editorAgent;
+    }
+
+    @Override
+    public void updateInPerspective(@NotNull ActionEvent event) {
+        final EditorPartPresenter editor = editorAgent.getActiveEditor();
+        boolean isCanDoOperation = false;
+
+        HandlesTextOperations handlesOperations;
+        if (editor instanceof HandlesTextOperations) {
+            handlesOperations = (HandlesTextOperations)editor;
+            isCanDoOperation = handlesOperations.canDoOperation(TextEditorOperations.SIGNATURE_HELP);
+        }
+
+        event.getPresentation().setEnabledAndVisible(isCanDoOperation);
+    }
+
+    @Override
+    public void actionPerformed(ActionEvent e) {
+        final EditorPartPresenter editor = editorAgent.getActiveEditor();
+        HandlesTextOperations handlesOperations;
+        if (editor instanceof HandlesTextOperations) {
+            handlesOperations = (HandlesTextOperations)editor;
+            if (handlesOperations.canDoOperation(TextEditorOperations.SIGNATURE_HELP)) {
+                handlesOperations.doOperation(TextEditorOperations.SIGNATURE_HELP);
+            }
+        }
+    }
+}

ide/che-core-ide-app/src/main/java/org/eclipse/che/ide/client/WorkspaceStateRestorer.java

@@ -20,6 +20,8 @@
 import org.eclipse.che.ide.statepersistance.AppStateManager;
 
 /**
+ * Restore workspace state, like opened files.
+ *
  * @author Evgen Vidolob
  */
 @Singleton

ide/che-core-ide-app/src/main/java/org/eclipse/che/ide/core/StandardComponentInitializer.java

@@ -43,6 +43,7 @@
 import org.eclipse.che.ide.actions.ShowHiddenFilesAction;
 import org.eclipse.che.ide.actions.ShowPreferencesAction;
 import org.eclipse.che.ide.actions.ShowReferenceAction;
+import org.eclipse.che.ide.actions.SignatureHelpAction;
 import org.eclipse.che.ide.actions.UndoAction;
 import org.eclipse.che.ide.actions.UploadFileAction;
 import org.eclipse.che.ide.actions.UploadFolderAction;
@@ -296,6 +297,9 @@ public interface ParserResource extends ClientBundle {
     @Inject
     private RefreshPathAction refreshPathAction;
 
+    @Inject
+    private SignatureHelpAction signatureHelpAction;
+
     @Inject
     @Named("XMLFileType")
     private FileType xmlFile;
@@ -635,6 +639,7 @@ public void initialize() {
         editorTabContextMenu.add(splitHorizontallyAction);
 
         actionManager.registerAction("noOpAction", new NoOpAction());
+        actionManager.registerAction("signatureHelp", signatureHelpAction);
 
         // Define hot-keys
         keyBinding.getGlobal().addKey(new KeyBuilder().action().alt().charCode('n').build(), "navigateToFile");
@@ -652,8 +657,10 @@ public void initialize() {
 
         if (UserAgent.isMac()) {
             keyBinding.getGlobal().addKey(new KeyBuilder().control().charCode('w').build(), "closeActiveEditor");
+            keyBinding.getGlobal().addKey(new KeyBuilder().control().charCode('p').build(), "signatureHelp");
         } else {
             keyBinding.getGlobal().addKey(new KeyBuilder().alt().charCode('w').build(), "closeActiveEditor");
+            keyBinding.getGlobal().addKey(new KeyBuilder().action().charCode('p').build(), "signatureHelp");
         }
     }
 

ide/che-core-ide-app/src/main/resources/org/eclipse/che/ide/CoreLocalizationConstant.properties

@@ -85,6 +85,10 @@ appearance.category = IDE
 format.name = Format
 format.description = Formatter of Code
 
+############### Signature Help #####################
+signature.name = Signature Help
+signature.description = Signature Help
+
 ############### Undo ###############################
 undo.name = Undo
 undo.description = Undo the most recent document action.